All bacterial-ripened cheeses contain nonstarter lactic acid bacteria that enter cheese through processing equipment or milk and grow to high numbers during ripening. Nonstarter lactic acid bacteria can have a significant effect on flavour development, but little is known about the factors that influence the growth and composition of the cheese nonstarter biota. As a result, the types and numbers of NSLAB in cheese, and their impact on flavour, is still largely a matter of chance. This paper examines the interaction between cheese ecology, adjunct use, and populations of nonstarter lactic bacteria.